This invention relates to process variable transmitters which are optically energized and provide optical outputs representing the process variable.
The terms light, optic, and radiation as used herein refer to visible and invisible electromagnetic radiation with wavelengths shorter than about 100 microns (100,000 nanometers); the terms electric, electrical used herein refer to lower frequency phenomenon such as commonly occur in electronic circuits operating at frequencies below 100 MHz. The term "process variable" used herein refers to a variable such as pressure, temperature, flow, velocity, specific gravity, etc. sensed by a transmitter such as a process control or aerospace instrument.